Engine starter control apparatus



J 1956 D. D. STOLTMAN 2,

ENGINE STARTER CONTROL APPARATUS Filed June 22, 1953 5 Sheets-Sheet 2 vwa /2 Hum! 15 74 INVENTOR.

DONALD D. 57'0L7'M4N June 5, 1956 D -$TQ| TMAN 2,748,760

ENGINE STARTER CONTROL APPARATUS Filed June 22, 1953 5 SheetsSheet 5INVENTOR. DOA/41. v D. 51-01. THAN EL, KM

q/ ATTORNEY Donald D. Stoltman, Conesus, N. Y., assignor to GeneralMotors Corporation, Detroit, Mich., a corporation of DelawareApplication June 22, 1953, Serial No. 363,325

13 Claims. (Cl. 123-179) This invention relates to starting apparatusfor internal combustion engines of the semi-automatic type in which acontrol circuit for the starting motor is automatically closed byoperation of one of the control members for controlling operation of theengine, such, for example, as the carburetor throttle valve.

In any engine starting apparatus it is particularly desirable to effectstarting as quickly as possible after closing of the starting motorcircuit in order to prevent unnecessary drain upon the battery. Also,where the starting apparatus is controlled by operation of thecarburetor throttle, it is essential that when the engine isself-operative the means through which the control switch for thestarting apparatus is actuated by the carburetor throttle operatingmeans must be in some way rendered inoperative so that the normaloperation of the throttle to variably control the engine speed will noteifect closing of the starter circuit.

It has been customary in starting apparatus of this type to provide acontrol switch operated in conjunction with the throttle which is soconstructed that it is closed when the throttle is opened to that extentwhich is best for starting in order to minimize the cranking period andwhen the engine begins to operate under its own power, engine suctionbecomes eifective to open this control switch and the suction isutilized to hold the switch open while the engine continues to operate.It has also been found that under some engine operating conditions as,for example, when an automotive vehicle is ascending a steep grade, withwide open throttle, the engine suction drops to such an extent that suchsuction is no greater than that which is maintained during cranking ofthe engine. In fact, under somewhat extreme conditions, the suctionduring running of the engine becomes actually less than that maintainedduring cranking when the engine is hot. It has therefore been founddifficult to design a starting device of this type having a controlswitch operated by engine suction in which suction will always beeffective to prevent closing of the switch during self-operation of theengine but which will never be effective to open the control switchduring the cranking period.

it is accordingly the principal object of the present invention toprovide an engine starting apparatus of the type referred to having acontrol switch of novel construction which is closed by thethrottleafter the latter has made a predetermined movement of the desired extenttoward open position and in which the control switch is opened by enginesuction when the engine becomes self-operative and which is providedwith means to cause a greater pressure difierential to be elfective tohold the switch open during all self-operation of the engine under themost extreme possible operating conditions than is ever elfective tomove the control switch to its open position during engine cranking.

A further object of the invention is to provide an engine startingapparatus having a control switch and means for operating it in themanner described which is simple nited States Patent F Patented June 5,1956 in construction, is positive in action, easy to manufacture andinexpensive.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

Figure 1 is a diagrammatic view of a starter circuit and throttlecontrol switch constructed in accordance with the present invention;

Figure 2 is a vertical section through the starter switch on line 22 ofFigure 5, with the parts in circuit closing position;

Figure 3 is a composite section with the parts in the circuit openposition, and on line 33 of Figure 4;

Figure 4 is an end elevation of the switch housing as seen from the leftin Figure 1;

Figure 5 is a section on line 5-5 of Figure 2;

Figure 6 is a fragmentary section on the same line but with certain ofthe parts shown in difiierent positions;

Figure 7 is an end elevation of the contact member es; and

Figure 8 is an exploded view of the switch showing the parts inperspective and some of the parts in longitudinal section.

As shown in the drawings, 10 indicates the mixture passage of thecarburetor for an internal combustion engine in which a throttle valve12 is rotatably mounted in suitable bearings 14 to variably control thequantity of mixture supplied to the engine in the usual way. As usual,the carburetor is provided with a flange 16 for attachment to the intakemanifold. A starter switch indicated generally by the numeral 18 ismounted on a boss 15 projecting from the wall of passage 10 where asshown, it is held in adjusted position by a spring 20 pressing against acap 22 and a bolt 24 extends through the spring and is threaded into thewall of the mixture passage at 26. However, it will be understood thatthe manner of securing the switch 18 in position is not material and itmay be held in position in any suitable manner.

As shown in Fig. l, the base 28 of switch 18 is held against the boss 15and surrounds the end 30 of the throttle shaft while the interior of theswitch 18 is connected with the mixture passage 10 posterior to thethrottle by a passage 32 in the boss 15. The specific means for mountingthe switch 18 which is disclosed permits easy rotary adjustment withrespect to the boss 15 and also permits easy removal of the switch bymerely lifting and rotating the spring member 20.

Switch 18 has electrical terminals 34 and 36 for connection with acurrent source 38 and with a control circuit which will be described indetail later. When the switch 13 is closed, a solenoid 39 is energizedand this effects the closing of a switch 4% to connect the startingmotor 43. directly with the current source. The ignition switch 52 is inseries with the terminals 34 and 36 so that both the ignition switch andthe switch 18 can be closed to cause the starting motor to becomeoperative. Closing of the switch 13 is effected by a predeterminedopening movement of the throttle valve 12 and the extent of this openingmovement can be varied by rotating the switch 18 on the boss 15. Thisadjustment will be more particularly discussed later.

The switch 18 comprises a cylindrical housing 46 of some suitableinsulating material in the walls of which are embedded the terminals 34and 36 previously referred to and these connect, respectively, withmetal strips 48 and 5'!) which terminate, respectively, in contacts 52and 54 which are suitably positioned in the solid head member 56 ofthecylindrical housing 46. This head member 56 has an axial bore 58 inwhich notches 60 are situated diametrically opposite each other andthese notches form passageways which extend through the head member fora purpose later set forth. The contacts 52 and 54 previously referred toare in the form of semispherical depressions 62 and the head member 56is provided with recesses 64 of semi-spherical shape which are spacedfrom each other and are the same distance from the center of the headmember. These semi-spherical depressions 62 are engageable by therounded heads of contact members 66 carried by a rotatable member 62;which is rotatable within the housing 46 by rotation of the throttleshaft.

The rotatable member 68 is provided with a stem or shaft 70 which isboth rotatable and slidable in the bore 58 of the head member 56. Thisrotatable member 68 has oppositely extending segments 72 each of whichsupports one of the contact members 66 and has a projecting flange 74extending through an arc of about 90 with respect to the axis of theshaft 70. Also, the member 68 on the side opposite the stem 70 has asecond and somewhat longer stem 76 in alignment with the stem 70, Thisstem 76 has a groove 78 in which are anchored the ends 80 and 82 of ahelical spring 84 which is provided with a central loop 86 that engagesin a groove 88 which is formed in the cylindrical wall of a rotatabledriving sleeve 92 which has a projecting flange 94 that fits within theprojecting flanges 74 of the rotatable members 68. At its other end thesleeve 92 has a somewhat smaller inner diameter into which the stem 76extends so that such stem is both slidable and rotatable in this portionof the sleeve 92. The left end of the sleeve 92 is closed except for acylindrical opening 97 which is provided with keyways 98. At the rightend the throttle shaft 30 is of reduced size, as indicated at 99 so thatit can extend into the opening 97 and has splines 100 on its outersurface which will engage the keyways 98 when the sleeve 92 is in theposition shown in Fig. 2. When the parts are so engaged, rotation of thethrottle shaft will rotate the sleeve 92 as the throttle is moved towardopen or closed position.

When the switch 18 is held in position on the boss 15, as shown in thedrawing, a spring 102 which is positioned within the housing 46 aroundthe sleeve 92 has one end engaging the boss and its other end engagesthe flange 94 on sleeve 92 so as to force the sleeve 92 into engagementwith the rotatable member 68 and exerts a pressure on such member whichtends to force the member 68 into engagement with the head member 56 andto hold the sleeve in the Fig. 2 position where it is engageable by thesplines 100 formed on the throttle shaft. When the parts are in thisposition, the contact members 66 will normally engage either thedepressions 64 formed in the head member 56 when the switch 18 is openedor the depressions 62 in the contact elements 54 when the switch isclosed.

As already indicated, the splines 100 and keyways 98 comprise a drivingconnection between the end of the throttle shaft and the sleeve 92 toeffect rotation of the latter when the throttle shaft is moved. Rotationof the sleeve 92 will, through the medium of spring 84 effect rotationof the rotatable member 68 to close the switch 18 in a manner more fullydescribed later. Opening movement of the switch when the engine beginsto run under its own power is effected by axial movement of the member68 and that movement is accomplished by a device operable in response toincrease in engine suction and which will now be described.

A flexible diaphragm 104 is subject to engine suction and carries a pin106 which extends into an axial recess in the stem 70. The pin has areduced portion which extends through the diaphragm and clamped betweena shoulder 107 of the pin and the diaphgram on one side of the latter isa disc 108 while on the opposite side, the pin is riveted over a washerto hold the diaphragm assembly together. The outer edge of the diaphragmis held against the outer edge of head 66 with sufiicient force to forman air-tight joint by crimping the outer edge of the cap 22 around theperipherally extending flange 112 of the member 56. The main portion ofthe cap 22 which is designated 111 is generally conical in shape, whileat the central part of the cap, which is in alignment with the stem 70,there is provided a domeshaped part 110, for a purpose to be laterdescribed. Extending from the part is a pointed projection 114 whichengages an opening 115 in the spring clip 20 when the switch is held inposition on the boss 115. Openings connect the space between the cap 22and the head 56 with the atmosphere.

When the parts are in the normal position, that is, when the engine isnot running, and is being cranked by the starting motor, they are asshown in Fig. 2, the diaphragm 104 is in contact with the surface of cap22 at all parts of the surface of the latter except at the dome 110,being held in this position by the force of the spring 102. The onlypart of the diaphragm which is subject to atmospheric pressure with theparts in this position is the small central portion of the diaphragmwhich lies opposite the dome portion 110 of cap 22, due to the fact thata seal is effected between the balance of the diaphragm and the conicalpart of the cap 22. When the engine is cranked by the starting motor,the suction which is maintained in the mixture passage 10 posterior tothe throttle is communicated through passage 32, through the small spacearound the member 68 between it and the inner wall of housing 46 andthrough passages 60 to the space between the diaphragm and the head 56.During cranking, this suction is very low and the small pressureditterential created across that part of the diaphragm which is subjectto atmospheric pressure is never sufficient to overcome the force ofspring 102 and move the diaphragm to the left, which is necessary toeffect opening of the switch.

However, when the engine begins to operate under its own power thesuction in passage 10 between the throttle and the engine is verygreatly increased, becoming as much as 18 inches of mercury. This willcreate a pressure differential across the small part of the diaphragmwhich is subject to atmospheric pressure that is great enough to movethe diaphragm and member 68 to the left and open the switch. After theengine is running and the switch is open, the parts are in the positionshown in Fig. 3 and the entire diaphragm is subject to atmosphericpressure. Under such conditions, the pressure differential across thewhole diaphragm is always great enough even if the engine suction whichis communicated to the diaphragm becomes actually less than that whichis communicated thereto during cranking, to prevent movement of thediaphragm to the right far enough to effect closing of the controlswitch.

As already stated, the switch is closed by manual movement of thethrottle 12 from its closed position toward open position. When theengine is not running and the throttle is closed, the switch 18 is openand the parts are in the Fig. 6 position. In this position, the contactmembers 66 engage the recesses 64 and the segments 74 are in a positionwhere the edges 122 of such segments engage stops 124 formed on thehousing 46. With the parts in this position, if the throttle is opened,the sleeve 92 is moved counter-clockwise, as seen in Fig. 6. Due toengagement of the bent part of spring 84 in groove 88, this rotation ofthe sleeve will rotate the element 68 after the spring is put undersufficient tension to disengage the members 66 from the recesses 64. Inorder to effect this disengagement, the spring 84 is put undersufiicient tension to move the member 68 with a snap action to theposition shown in Fig. 5 in which the opposite edge 126 of such segment74 is in engagement with a stop shoulder 128 formed on housing 46 andcontact members 66 have been moved into engagement with the contacts 62.This F Will eifect closing of the switch 18 and, if the switch 42 isclosed, will effect closing of the control circuit of the starting motorand energization' thereof.

When the engine is in operation, if the member 68 can be, under anycircumstances, rotated with the throttle as the latter is moved towardopen or closed position, it will be moved without opposition becausecontact members 66 are not in engagement with either recesses 64 orcontacts, and member 68 can rotate entirely freely.

Obviously, the rotational movement of member 68 is limited by stops 124and 128 but the sleeve 92 and the throttle shaft can continue to rotateafter movement of member 68 is stopped because of the yielding springconnection 84 between sleeve 92 and member 68.

The abutment or stop 128 on housing 46 is formed by an undercut 130 fromthe edge 132 of a rib 134 formed on the inner surface of housing 46. Informing this abutment, a shoulder 138 is also formed which limits themaximum movement of member 68 to the left when the switch is opened bythe effect of engine suction.

When the switch is opened by the effect of high suction, the shoulder138 permits enough movement of member 68 to move the sleeve 92 farenough to the left to disengage the contacts but not far enough todisengage the lteyways 98 from splines 100 so as to uncouple the drivingconnection between the throttle shaft and sleeve 92. To accomplish thisthe throttle must be permitted to close. This will disengage the segment68 from shoulder 13$ and when this occurs the segment and sleeve 92 willmove far enough to the left to uncouple the driving connection andsleeve 92 and segment 68 will have been moved substantially back totheir normal position with the contact members 66 in alignment withrecesses 64, in which position such elements are held by spring 84 untilthe driving connection with the throttle shaft is reestablished.Therefore, even if the suction in passage posterior to the throttledropped enough to permit movement of the member 68 far enough to theright to engage the contact members 66 with the head of housing 46, thismovement could not take place because of the engagement of the end ofsleeve 92 with the splines 150 which would not be in alignment with thekeyways 98 when the suction drops on open throttle. This mechanismconstitutes a positively operating means for preventing any closure ofthe control switch 18 when the engine is in operation.

Due to the selective mounting of the housing 46 on the boss concentricwith the shaft 30, it is possible to adjust the angular relation of thecontacts with respect to the throttle shaft so that completion of thecircuit will be made only when the opening of the throttle valve 12 isbest suited for engine starting. Such indexing of the switch can beaccomplished by setting the throttle position which is determined to bebest suitable for engine starting, and thence rotating the switch on theboss until the contactor snaps from the open circuit relation to theclosed circuit relation. When secured in that relation, starting isaccomplished by movement of the accelerator lever until the throttlereaches the position it occupied when the switch was indexed, and whenthis position is reached, the control switch will be closed.

The control circuit of the starting apparatus in which this controlswitch is used is not material and it may be exactly like that shown inthe patent to Dermond, 2,326,125, of August 10, 1943. The principalelements of this circuit are shown herein and comprise a wire 140leading from the battery 38 to switch 42 which connects the battery withthe ignition and with terminal 34 of the switch 13. A wire 142 leadsfrom the terminal 36 of switch 18 to the winding of a relay switch 144and thence to ground through the generator, so that closing of theswitch is merely energizes the winding of the relay switch. A Wire 146leads from the battery to one of the contacts of the relay switch, whilethe cooperating contact of such switch is connected by a wire 148 to onecoil of a two-coil magnet 150 grounded at 152. The wire 148 is alsoconnected by wire 154 to the second, coil of the 6 magnet which isconnected by wire 156 to a wire leading to the starting motor 41 and toground at 160.

The wire 146 also leads to a fixed contact 162 and another fixed contact164 is connected by a wire 166 with the starting motor, this wire alsoconnecting with the wire 156 previously referred to. The movable contact40, previously referred to, is moved by the magnet 15!) into engagementwith contacts 162 and 164 to close the starting motor circuit and causeoperation of the starting motor. When the switch 18 is closed, thecontacts of the relay switch are closed and both coils of the magnet 15%are energized to close the switch 49. When this takes place, one of thecoils of the magnet is short-circuited and the switch 40 is held closeduntil the engine is started. When switch 18 is opened, magnet 159 isentirely deenergized and switch 40 is opened.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. In a starting apparatus for internal combustion engines having astarting motor, a current source, a circuit for connecting said motorand current source, a control switch for controlling said circuit havinga plurality of contacts adapted to be electrically connected to closesaid circuit, a member rotatably movable to connect said contacts andaxially movable by engine suction to a position to prevent closing ofthe switch during engine operation, and means opposing a predeterminedresistance to movement of said suction operated member to switch closingposition, operating means for moving said rotatable member to switchclosing position, a resilient operatng connection between said means andthe rotatable member, said resilient operating connection beingeffective to exert sufficient force to overcome the means opposingmovement of said rotatable member only after a predetermined movement ofsaid operating means.

2. In a starting apparatus for an internal combustion engine having acarburetor provided with a mixture passage for supplying combustiblemixture to the engine and a throttle valve for controlling the quantityof mixture supplied thereby, a current source, a starting motor operableby current from said source and a circuit for connecting said startingmotor with the current source; a control switch for controlling saidcircuit comprising a housing mounted on the carburetor, a rotatablecontact member having contacts mounted thereon, said member beingnormally in switch open position and rotatable to a position to closesaid switch to cause operation of the starting motor, means normallyconnecting said rotatable member with the throttle valve for operationthereby, means operable when the engine is self-operative for disablingthe connection between the throttle valve and said rotating member andfor moving said rotatable member to a position to open the controlswitch, and means etfective under all operating conditions to preventmovement of the rotatable member to a position to open the switch whilethe engine is being operated by the starting motor.

3. In a starting apparatus for an internal combustion engine having acarburetor provided with a mixture passage for supplying combustiblemixture to the engine and a throttle valve for controlling the quantityof mixture supplied thereby, a current source, a starting motor operableby current from said source, and a circuit for connecting said startingmotor with the current source; a control switch for controlling saidcircuit comprising a housing mounted on the carburetor, a rotatablecontact member having contacts mounted thereon, said member beingnormally in switch open position and rotatable to a position to closesaid switch to cause operation of the starting motor, means normallyconnecting said rotatable member with the throttle valve for operationthereby, suction operated means for disabling the operating connectionbetween the throttle valve and the rotating member, said suctionoperated means being so constructed that 7 it is effective to disablesaid operating connection under all possible conditions ofself-operation of the engine and is never effective to disable saidoperating connection during operation of the engine by the startingmotor.

4. In a starting apparatus for an internal combustion engine having acarburetor provided with a mixture passage for supplying combustiblemixture to the engine and a throttle valve for controlling the quantityof mixture supplied thereby, a current source, a starting motor operableby current from said source and a circuit for connecting said startingmotor with the current source; a control switch for controlling saidcircuit comprising a housing mounted on the carburetor, a rotatablemember within the housing and having contacts mounted thereon, anoperating member resiliently connected to said rotatable member, meansfor operatively connecting said operating member with the throttle valvefor operation therewith, means operable by engine suction when theengine is selfoperative to disable the connection between the operatingmember and throttle shaft and means under all operating conditionspreventing the disabling of this connection when the engine is beingoperated by the starting motor.

5. In a starting apparatus for an internal combustion engine having acarburetor provided with a mixture passage for supplying combustiblemixture to the engine and a throttle valve for controlling the quantityof mixture supplied thereby, a current source, a starting motor operableby current from said source, and a circuit for connecting said startingmotor with the current source;

a control switch for controlling said circuit comprising a housingmounted on the carburetor, a rotatable contact member having contactsmounted thereon, said member being normally in switch open position androtatable to a position to close said switch to cause operation of thestarting motor, means normally connecting said rotatable member with thethrottle valve for operation thereby, and means for adjustably securingthe switch housing to the carburetor, said means being constructed topermit rotary adjustment of the switch housing relative to the throttlein order to vary the movement of the throttle required to move saidrotatable member to its switch closing position.

6. In a starting apparatus for an internal combustion engine having acarburetor provided with a mixture passage for supplying combustiblemixture to the engine and a throttle valve for controlling the quantityof mixture supplied thereby, a current source, a starting motor operableby current from said source and a circuit for connecting said startingmotor with the current source; a control switch for controlling saidcircuit comprising a housing mounted on the carburetor, a rotatablemember within the housing and having contacts mounted thereon, anoperating member resiliently connected to said rotatable member. suctionoperated means for disabling the operating connection between thethrottle valve and the rotating member, said suction operated meansbeing so constructed that it is effective to disable said operatingconnection under all possible conditions of self operation of theengine, and is never effective to disable said operating connectionduring operation of the engine by the starting motor.

7. In a starting apparatus for an internal combustion engine having acarburetor provided with a mixture passage for supplying combustiblemixture to the engine and a throttle valve controlling the quantity ofmixture supplied thereby, a current source, a starting motor operable bycurrent from said source and a circuit for connecting the starting motorwith the current source; a control switch for controlling said circuitcomprising a housing mounted on the carburetor, a rotatable membernormally operatively connected to the throttle and rotatable thereby toa position to effect closing of the control switch. said member beingmovable axially with respect to the throttle to effect opening of theswitch and disconnection of said member from the throttle, a suctionoperated member operable to move said rotatable member axially, meansfor communicating the suction of the mixture passage posterior to saidthrottle to said suction operated member, and means whereby the samedegree of suction creates a greater pressure differential across saidsuction operated member when the engine is self operative than when theengine is being operated by the starting motor.

8. In a starting apparatus for an internal combustion engine having acarburetor provided with a mixture passage for supplying combustiblemixture to the engine and a throttle valve controlling the quantity ofmixture supplied thereby, a current source, a starting motor operable bycurrent from said source and a circuit for connecting the starting motorwith the current source; a control switch for controlling said circuitcomprising :1 housing mounted on the carburetor, a rotatable membernormally operatively connected to the throttle and rotatable thereby toa position to effect closing of the control switch, said member beingmovable axially with re spect to the throttle to effect opening of theswitch and disconnection of said member from the throttle, a suctionoperated member operable to move said rotatable member axially, meansfor communicating the suction of the mixture passage to the entire areaof one side of said suction operated member, means operable when theengine is being operated by the starting motor for communicatingatmospheric pressure to a part only of the opposite side of said suctionoperated member, whereby the pressure differential effective on saidmember is insufficient to effect movement thereof and opening of theswitch while the engine is being operated by the starting motor.

9. in a starting apparatus for an internal combustion engine having acarburetor provided with a mixture passage for supplying combustiblemixture to the engine and a throttle valve controlling the quantity ofmixture supplied thereby, a current source, a starting motor operable bycurrent from said source and a circuit for connecting the starting motorwith the current source; a control switch for controlling said circuitcomprising a housing mounted on the carburetor, a rotatable membernormally operatively connected to the throttle and rotatable thereby toa position to effect closing of the control switch, said member beingmovable axially with respect to the throttle to effect opening of theswitch and disconnection of said member from the throttle, a suctionoperated member operable to move said rotatable member axially, meansfor communicating the suction of the mixture passage to the entire areaof one side of said suction operated member, means operable when theengine is being operated by the starting motor for communicatingatmospheric pressure to a part only of the opposite side of said suctionoperated member, said means being operable when the engine is selfoperative to communicate atmospheric pressure to the entire area of theopposite side of said suction operated member, whereby the pressuredifferential effective on said member is insufficient to effect openingof the switch during opera tion of the engine by the starting motor butis always sufiicient during self operation of the engine to preventclosing of said control switch.

10. In a starting apparatus for an internal combustion engine having acarburetor provided with a mixture pas sage for supplying combustiblemixture to the engine and a throttle valve controlling the quantity ofmixture supplied thereby, a current source, a starting motor operable bycurrent from said source and a circuit for connecting the starting motorwith the current source; a control switch for controlling said circuitcomprising a housing mounted on the carburetor, a rotatable membernormally operatively connected to the throttle and rotatable thereby toa position to effect closing of the control switch, said member beingmovable axially with respect to the throttle to effect opening of theswitch and disconnection of said member from the throttle, a flexiblediaphragm movable by engine suction and operable to move said rotatablemember axially to open said control, and means whereby the same degreeof engine suction creates a greater pressure dilterential across saiddiaphragm when the engine is self operative than when the engine isbeing operated by the starting motor, so that a degree of suction whichis sufiicient to hold the switch open during self operation of theengine is not sulficient to open the switch While the engine is beingoperated by the starting motor.

11. In a starting apparatus for an internal combustion engine having acarburetor provide-d with a mixture passage for supplying combustiblemixture to the engine and a throttle valve controlling the quantity ofmixture supplied thereby, a current source, a starting motor operable bycurrent from said source and a circuit for connecting the starting motorwith the current source; a control switch for controlling said circuitcomprising a housing mounted on the carburetor, a rotatable membernormally operatively connected to the throttle and rotatable thereby toa position to efiect closing of the control switch, said member beingmovable axially with respect to the throttle to effect opening of theswitch and disconnection of said member from the throttle, a suctionoperated diaphragm effective to move said rotatable member axially toopen the switch and to disable the operating connection between therotatable member and the throttle means whereby a given degree of enginesuction will create a suflicient pressure differential across thediaphragm to open the switch and disable the driving connection when theengine is self operative, and means for preventing the same degree ofengine suction from operating the diaphragm when the engine is beingoperated by the starting motor.

12. In a starting apparatus for internal combustion engines having astarting motor, a current source, a control switch for controlling saidcircuit having a plurality of contacts adapted to be electricallyconnected to close said circuit, a member rotatably movable to connectsaid contacts and axially movable by engine suction to a position toprevent closing of the switch during engine operation, a housingsurrounding said rotatable member and in which the member is rotatablyand axially movable, and abutments formed on the inner wall of saidhousing for limiting the rotating and axial movements of said rotatablemember.

13. In a starting apparatus for an internal combustion engine having acarburetor provided with a mixture passage for supplying combustiblemixture to the engine and a throttle valve controlling the quantity ofmixture supplied thereby, a current source, a starting motor operable bycurrent from said source and a circuit for connecting the starting motorwith the current source; a control switch for controlling said circuitcomprising a housing mounted on the carburetor, a plurality of fixedcontacts supported by the housing, a rotatable member supporting aplurality of contacts and movable to engage said contacts with the fixedcontacts in order to close the control switch, said housing having aplurality of depressions formed therein normally engaged by the contactson said rotatable member and acting as a detent means to oppose movementof the rotatable member to switch closing position, a resilientoperating connection between the throttle valve and said rotatablemember, and eflfective after a predetermined opening movement of thethrottle to overcome the resistance of the detent means and move saidrotatable member to switch closing position.

Winkler et al. Mar. 4, 1941 Dyer Aug. 11, 1942

